**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** GLOBALLY, INTENSIFICATION OF AGRICULTURE HAS LEAD TO A DEGRADATION OF SOIL ORGANIC MATTER (SOM) IN AGROECOSYSTEMS. SOM IS AN IMPORTANT INDICATOR OF SOIL HEALTH, AS SOM ACTS LIKE A PANTRY FOR CROPS. IT IS ABLE TO HOLD ONTO THE WATER AND NUTRIENTS THAT PLANTS NEED, REDUCING THE NEED FOR EXCESSIVE IRRIGATION AND FERTILIZATION. THIS STUDY IS INVESTIGATING THE MECHANISMS OF SOM FORMATION UNDER COVER CROP MANAGEMENT. SPECIFICALLY, WE ARE INTERESTED IN QUANTIFYING THE CONTRIBUTION OF VOLATILE ORGANIC COMPOUNDS (VOCS) TO THE FORMATION OF SOM, AND IDENTIFYING THE SOIL MICROORGANISMS LINKED TO INCREASING VOC DERIVED SOIL ORGANIC MATTER. INCREASING SOM IN AGROECOSYSTEMS HAS THE POTENTIAL TO INCREASE FOOD PRODUCTION AND FOOD SECURITY IN THE UNITED STATES, WHILE ALSO MITIGATING CLIMATE CHANGE. SOM ALSO PROTECTS SOIL FROM SOME OF THE NEGATIVE EFFECTS OF DROUGHT. THUS, INCREASING SOM CAN INCREASE RESISTANCE TO DROUGHT, WHICH MAY BECOME INCREASINGLY IMPORTANT AS CHANGES IN PRECIPITATION REGIMES ARE EXPECTED TO CHANGE DRAMATICALLY IN SOME PLACES. FURTHERMORE, SOM MAY CONTRIBUTE TO NATIONAL SECURITY BY MITIGATING THE DESTABILIZING EFFECTS OF CLIMATE CHANGE AND FOOD SCARCITY.WE WILL MEASURE THE EFFECTS OF COVER CROPS ON SOIL HEALTH BY CONDUCTING LITTER DECOMPOSITION EXPERIMENTS IN A MANAGED AGROECOSYSTEM AND WE WILL MEASURE CHANGES IN SOIL ORGANIC MATTER, MICROBIAL COMMUNITY COMPOSITION, AND ECOSYSTEM FUNCTION. SPECIFICALLY WE WILL USE STABLE-ISOTOPE PROBING, A TECHNIQUE THAT USES A NATURAL LABEL, TO TRACK CARBON FROM COVER CROPS TO THE SOIL; AND WE WILL USE NEXT-GENERATION SEQUENCING TO CHARACTERIZE THE SOIL MICROBIAL COMMUNITY. WE WILL USE THESE DATA TO ESTABLISH LINKS BETWEEN COVER CROPS, SOIL HEALTH, AND THE SOIL MICROBIAL COMMUNITY. WE WILL DISTRIBUTE OUR FINDINGS THROUGH ACADEMIC AND NON-ACADEMIC PIPELINES, INCLUDING CONFERENCE PRESENTATIONS, PEER-REVIEWED PUBLICATIONS, AND WHITE PAPERS.ULTIMATELY, WE EXPECT THIS PROJECT TO PRODUCE RESULTS THAT WILL INFORM FARM MANAGERS HOW TO EFFECTIVELY MANAGE COVER CROPS FOR MAXIMUM SOIL ORGANIC MATTER PRODUCTION, AND INCREASED SOIL HEALTH. ULTIMATELY, THIS SHOULD RESULT IN GREATER CROP YIELDS, BOLSTERING THE UNITED STATES AGRICULTURAL INDUSTRY, AND REDUCING FOOD INSECURITY. WE ALSO INTEND TO CONTRIBUTE SIGNIFICANTLY TO OUR UNDERSTANDING OF THE CONTRIBUTIONS OF VOLATILE CARBON, AND SOIL MICROORGANISMS TO THE PRODUCTION OF SOIL ORGANIC MATTER, WHICH COULD BE USED TO INFORM MODELS OF SOIL ORGANIC MATTER FORMATION.